India plans to build thorium fast breeder reactors to breed U-233 for other reactors. This is the crux of the importance of thorium reserves of India.

India Developing Thorium Based Fast Breeder Nuclear Reactor

A team of scientists at a premier Indian nuclear facility has made a theoretical design of an innovative reactor that can run on thorium – available in abundance in the country – and will eventually do away with the need for uranium.

But the success of the project largely depends on the US playing ball. The novel Fast Thorium Breeder Reactor (FTBR) being developed by V. Jagannathan and his team at the Bhabha Atomic Research Centre (BARC) in Mumbai has received global attention after a paper was submitted to the International Conference on Emerging Nuclear Energy Systems (ICENES) held June 9-14 in Istanbul.

Power reactors of today mostly use a fissile fuel called uranium-235 (U-235), whose ‘fission’ releases energy and some ‘spare’ neutrons that maintain the chain reaction. But only seven out of 1,000 atoms of naturally occurring uranium are of this type. The rest are ‘fertile’, meaning they cannot fission but can be converted into fissionable plutonium by neutrons released by U-235.

Thorium, which occurs naturally, is another ‘fertile’ element that can be turned by neutrons into U-233, another uranium isotope. U-233 is the only other known fissionable material. It is also called the ‘third fuel’.

Thorium is three times more abundant in the earth’s crust than uranium but was never inducted into reactors because – unlike uranium – it has no fissionable atoms to start the chain reaction.

But once the world’s uranium runs out, thorium – and the depleted uranium discharged by today’s power reactors – could form the ‘fertile base’ for nuclear power generation, the BARC scientists claim in their paper.

They believe their FTBR is one such ‘candidate’ reactor that can produce energy from these two fertile materials with some help from fissile plutonium as a ‘seed’ to start the fire.

By using a judicious mix of ‘seed’ plutonium and fertile zones inside the core, the scientists show theoretically that their design can breed not one but two nuclear fuels – U-233 from thorium and plutonium from depleted uranium – within the same reactor.

This totally novel concept of fertile-to-fissile conversion has prompted its designers to christen their baby the Fast ‘Twin’ Breeder Reactor.

Their calculations show the sodium-cooled FTBR, while consuming 10.96 tonnes of plutonium to generate 1,000 MW of power, breeds 11.44 tonnes of plutonium and 0.88 tonnes of U-233 in a cycle length of two years.

According to the scientists, their FTBR design exploits the fact that U-233 is a better fissile material than plutonium. Secondly, they were able to maximise the breeding by putting the fertile materials inside the core rather than as a ‘blanket’ surrounding the core as done traditionally.

‘At present, there are no internal fertile blankets or fissile breeding zones in power reactors operating in the world,’ the paper claims.

The concept has won praise from nuclear experts elsewhere. ‘Core heterogeneity is the best way to help high conversion,’ says Alexis Nuttin, a French nuclear scientist at the LPSC Reactor Physics Group in Grenoble.

Thorium-based fuels and fuel cycles have been used in the past and are being developed in a few countries but are yet to be commercialised.

France is also studying a concept of ‘molten salt reactor’ where the fuel is in liquid form, while the US is considering a gas-cooled reactor using thorium. McLean, Virginia-based Thorium Power Ltd of the US, has been working with nuclear engineers and scientists of the Kurchatov Institute in Moscow for over a decade to develop designs that can be commercialised.

But BARC’s FTBR is claimed to be the first design that truly exploits the concept of ‘breeding’ in a reactor that uses thorium. The handful of fast breeder reactors (FBRs) in the world today – including the one India is building in Kalpakkam near Chennai – use plutonium as fuel.

These breeders have to wait until enough plutonium is accumulated through reprocessing of spent fuel discharged by thermal power reactors that run on uranium.

Herein lies the rub.

India does not have sufficient uranium to build enough thermal reactors to produce the plutonium needed for more FBRs of the Kalpakkam type. The India-US civilian nuclear deal was expected to enable India import uranium and reprocess spent fuel to recover plutonium for its FBRs. But this deal has hit a roadblock.

‘Jagannathan’s design is one way of utilising thorium and circumventing the delays in building plutonium-based FBRs,’ says former BARC director P.K. Iyengar.

Meanwhile, India’s 300,000 tonnes of thorium reserves – the third largest in the world – in the beach sands of Kerala and Orissa states are waiting to be tapped. The BARC scientists say that thorium should be inducted into power reactors when the uranium is still available, rather than after it is exhausted.

But the FTBR still needs an initial inventory of plutonium to kick-start the thorium cycle and eventually to generate electricity. A blanket ban on India re-processing imported uranium – a condition for nuclear cooperation with the US – could make India’s thorium programme a non-starter.

Iyengar has one suggestion that he says must be acceptable to the US if it is serious about helping India to solve its energy problem.

‘The US and Russia have piles of plutonium from dismantled nuclear weapons,’ Iyengar told IANS, adding: ‘They should allow us to borrow this plutonium needed to start our breeders. We can return the material after we breed enough.’

A breeder reactor is a nuclear reactor that consumes fissile and fertile material at the same time as it creates new fissile material. Production of fissile material in a reactor occurs by neutron irradiation of fertile material , particularly Uranium-238 and Thorium-232. In a breeder reactor, these materials are deliberately provided, either in the fuel or in a breeder blanket surrounding the core, or most commonly in both. Production of fissile material takes place to some extent in the fuel of all current commercial nuclear power reactors. Towards the end of its life, a uranium (not MOX, just uranium) PWR fuel element is producing more power from the fissioning of plutonium than from the remaining uranium-235. Historically, in order to be called a breeder, a reactor must be specifically designed to create more fissile material than it consumes…

The thermal breeder reactor. The excellent neutron capture characteristics of fissile Uranium-233 make it possible to build a heavy water moderated reactor that, after its initial fuel charge of enriched uranium, plutonium or MOX, requires only thorium as input to its fuel cycle. Thorium-232 produces Uranium-233 after neutron capture and beta decay…

The Advanced Heavy Water Reactor is one of the few proposed large-scale uses of thorium . As of 2006 only India is developing this technology. Indian interest is motivated by their substantial thorium reserves; almost a third of the world’s thorium reserves are in India, which in contrast has less than 1% of the world’s uranium. Their stated intention is to use both fast and thermal breeder reactors to supply both their own fuel and a surplus for non-breeding thermal power reactors. Total worldwide resources of thorium are roughly three times those of uranium, so in the extreme long term this technology may become of more general interest.

India to build prototype thorium reactor

The Indian Union cabinet cleared the Department of Atomic Energy ‘s proposal to set up a 500 MW prototype of the next generation fast breeder nuclear power reactor (FBR) at Kalpakkam, thereby setting the stage for the commercial exploitation of thorium as a fuel source. Bellona, 25/09-2003

Although uranium is the only naturally occurring fissile element directly usable in a nuclear reactor, the country only has 0.8 per cent of the world‘s uranium reserves and may have to depend on imports in the future. On the other hand, India has around 32 per cent of the world‘s reserves of thorium, and with a carefully planned program, indigenously available uranium can be used to harness the energy contained in non-fissile thorium to be used in the FBRs. Though the country ‘s atomic power program had produced only a little over 2,000 MW of nuclear energy over 34 years, the Indian Planning Commission has set an ambitious target of producing around 20,000 MW of nuclear power by 2020.

India has a so-called “three-stage nuclear program”. In the first stage, plutonium is created in its pressurized heavy water reactors (PHWRs) and extracted by reprocessing. In the second stage, fast breeder reactors (FBRs) use this plutonium in 70-percent MOX-fuel to breed uranium-233 in a thorium blanket around the core. In the final stage, the FBR’s use thorium-232 and produce uranium-233 for other reactors.

The first stage has been realized with India’s 10 nuclear power plants. The second stage is only realized by a small experimental fast breeder reactor (13 MW), at Kalpakkam. This reactor has a history with a lot of problems (as has been the case with the 10 nuclear reactors). This reactor is on top of a list of dangerous reactors in the country, according to a safety assessment of India’s Atomic Energy Regulatory Board. The reactor has a lack of safety measures and cooling systems.

THE construction of the Advanced Heavy Water Reactor (AHWR) is all set to begin this year. The AHWR will use thorium, the “fuel of the future”, which is in plenty in India, to generate 300 MWe of electricity up from its original design output of 235 MWe. The reactor will have a life of 100 years and may be built on the campus of the Bhabha Atomic Research Centre (BARC) at Trombay. Scientists and engineers at BARC have been working for several years on the development of the AHWR.

Expert committees of Nuclear Power Corporation of India Limited (NPCIL) have completed the peer review of the detailed project report. A team of persons other than designers, who were equally knowledgeable in reactor design, has reviewed the design.

Said Anil Kakodkar, Chairman, Atomic Energy Commission: “I asked them to carry out a review of its design because it has new, innovative concepts. We wanted to get an independent peer review done.” The team had made some suggestions for improving further the economy and constructability of the reactor. “But the soundness of the design is not in doubt,” said Kakodkar, whose dream project is the AHWR. “We want to do a similar review on safety. The first one was generic, dealing with constructability, economics, engineering and so on. We want now to do a more specific review of the safety of the reactor. For that we are compiling documents, and will present it to people,” he added.

The construction of the AHWR will mark the beginning of the third phase of India’s nuclear electricity generation programme. In the first phase, 12 Pressurised Heavy Water Reactors (PHWRs) were built and are operational in the country. They use natural uranium as fuel, and heavy water as both moderator and coolant. The second stage has begun with the construction of the Prototype Fast Breeder Reactor (PFBR of 500 MWe) at Kalpakkam, Tamil Nadu. The PFBR will use plutonium, a byproduct from the PHWRs, as fuel. The fuel for the AHWR will be a hybrid core, partly thorium-uranium 233 and partly thorium-plutonium. The three stages are interlinked. The AHWR will be a technology demonstrator for thorium utilisation.

The design philosophy of the AHWR is simple but challenging: enhanced safety at low cost. It will incorporate passive safety features, which do not require human intervention. It will have no circulating pumps. It is a system in which dependency on active components is minimised to a large extent. It has operator-forging characteristics.

B. Bhattacharjee, Director, BARC, said: “At the international level, the AHWR has been selected for a case study at the IAEA (International Atomic Energy Agency) for acceptance as per international standards for next generation reactors.”

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3 Responses to Thorium: energy independence for India

This is chanukya,want to ask one question about our capablity?is it require bow infront of US for uranium enrichment? we donot have knowledge to do ourselef?how much time it takes to do uranium enrichment by ourself,always begging kind of nature……………please i am requesting you to motivate the students or researchers in india in that passion.Do our nation to be pride.we are always with you people.